Endoscopic Assessment of Schneiderian Membrane Perforation During Osseodensification-mediated Transcrestal Sinus Floor Elevation With Graftless Immediate Implant Placement in Subsinus Bone Height of 4-6 mm: A Pilot Study.

Inclusion criteria

• males and females over 21 years of age;
• partial edentulism in the posterior maxilla involving 2 or more adjacent teeth in the premolar-molar area;
• teeth at the intended implant sites must have been extracted or lost at least 9 months before the date of implant surgery;
• sinus floor with a relatively flat contour confirmed on baseline CBCT;
• bucco-palatal sinus width (distance between the buccal and palatal walls at 10-mm apical level comprising the residual alveolar crest ) 8-12 mm confirmed on baseline CBCT to minimize the risk of SMP during surgery (Stacchi et al. 2022);
• sinus membrane thickness ≤ 2 mm;
• subsinus residual bone height (RBH) 4-6 mm at the intended implant sites and bucco-palatal bone width allowing implant placement without bone augmentation procedures.

Exclusion criteria

• systemic conditions contraindicating implant surgery;
• pregnancy or lactation;
• ongoing or history of pathologies or medications affecting bone metabolism;
• ongoing or history of head and neck irradiation;
• oral inflammatory and autoimmune diseases;
• presence of osseous lesions or persistent infections in the planned implant sites;
• previous bone augmentation surgery;
• uncontrolled periodontal diseases;
• heavy smoking (> 10 cigarettes/day);
• history of sinus surgery;
• presence of intrasinus bony septa that could affect membrane elevation and distention; and
• ongoing or history of rhinitis or sinusitis.